Friel Zones vs. Straight Percentages

Okay, so I'm a newb to the whole heart zone training thing, but I thought that getting a HRM computer (Garmin 500) and Friel's book Total Heart Training would get me all squared away.

Not quite!

I've had the monitor for a week+ of riding, and have been homing in on my Lactate Threshold by evaluating my perceived effort. I'm about to schedule a metabolic test to confirm things, but let's assume I am correct that I hit my LT at 167 bpm. I've used Joe's LT based charts to enter zones into my Garmin 500, however I'm facing a disconnect when trying to use the MaxHR% data of the 500 to have precise information. Friel's approach is very precise. There is a distinct difference between being at the bottom of a zone versus the top, particular when you venture into Zone 5, which he breaks down in 5a, 5b, and 5c. So using the Zone data of the 500 is precise enough, but using MaxHR% results in this:

Keeping LT (the start of Zone 5) the same, there is a significant range of heart rate where Friel places you in a lower zone than the straight percentages indicate. That's especially significant given Friel recommends minimizing time in Zone 3 for road cyclists, preferring either lighter zone 2, or heavier zone 4, training.

Unless I'm missing something (would could very easily be true, given my total newb status), what this says to me is that any training program needs to be very specific concerning the definition of the zones it is using. A Friel training plan only works using his definition of the zones, and other training plans would need to be modified to reflect the zone definitions.

"If you're riding less than 18 MPH up a 2% grade please tell people Coggan is coaching you."

Do you just use the zones and accept not being as precise? The 500 will only handle 5 zones, buy you can set the max to the top of Zone 5a and it will show a "Zone 6" when that is exceeded.

I don't use HR zones any more but when I did I would just figure out what my LTHR and do threshold workouts around there and easy workouts in zone 2. I wouldn't worry about being too precise, especially with the higher zones 5a-c. It's very difficult to use HR for the shorter intervals where you typically hit those HR zones. The reason being when you do a constant effort/power interval your HR doesn't respond quickly enough to be useful.

Here is an example of some hill repeats I did this summer. My power or effort for the intervals was well above threshold but my HR only barely reached threshold at the end of the interval. I mostly did these by perceived exertion and looked at the power later.

I'm with Greg. I tried Friel's zones, found I overtrained much too easily with them. I do a percentage thing off LTHR. Top of my recovery zone 2 is about 75% of MHR. IMO, that's the only really good fixed boundary. Push that Z2 top and you'll overdo it with nothing to show for it, either. Some people use a recovery Z2 and an endurance Z2. I think that's overly complicated.

Appreciate the responses, guys - what you are saying makes sense. With more monitor experience under my belt, I'm sure the rates themselves will have more meaning, and I won't need to rely on the Garmin's Max% or zones. After a week and a half, I already know some rates that are clearly transition points. I just don't know from what to what, so it's hard to relate what I'm doing to the training guides. As I've said, I'm a total newb that wants to get fitter and faster.

Carbon... did you determine recovery zone 2 using perceived effort, or is that something determined by test?

I'm seriously considering a metabolic test to get my initial thresholds nailed down. The rehab place that does them here had a drawing at the Tour de Scottsdale, but alas I didn't win.

"If you're riding less than 18 MPH up a 2% grade please tell people Coggan is coaching you."

I like setting my HR zones on Chris Carmicheals approach. Do some research on his heart zone stuff online, and how to do his test, and you should have a good basis of your zones. Also, don't take the zones too seriously, it's not the end of the world if you train 1 or 2 or even 5 bpm off from what were your trying. Too many things affect HR daily and can change your results. Hope that helps some.

Carbon... did you determine recovery zone 2 using perceived effort, or is that something determined by test?

I'm seriously considering a metabolic test to get my initial thresholds nailed down. The rehab place that does them here had a drawing at the Tour de Scottsdale, but alas I didn't win.

Oh no! The truth comes out. I use PC Coach Cycling Plan. It just assigned me that number from my input of tested MHR, and I've found it to be just right over the years. Nice exertion, good workout, but not much training load. OTOH, the Plan's estimate of my LT is never particularly close. I know the RZ2 is usually done off MHR and LT is by test, so that sort of makes sense.

I don't know if there are tests for anything other than LT. And it's so easy to get LT and then it always moves around on me anyway, so I don't see spending money on it unless it was a business expense.